In wafer manufacture probing is a process for testing if dies formed on a wafer are functional. Probing dies on a wafer involves penetrating the surface of the wafer at predetermined points to make contact with the pads of each die. The probe uses probe needles to make contact with the pads of each die. Once the probe has penetrated the surface of the die an electronic signal is passed through the die from at least one probe needle to at least one other probe needle. Information received from the probe needle(s) is used to determine the functionality of the die.
Problems may arise in the probing process due to a number of different reasons. These reasons include dirt being trapped on the probing needles, surface residue building up on the probing needles, and the probing needles becoming bent out of shape.
At present an operator reviews the probe results and judges whether there is a probing issue by visual inspection of failed wafer results or low yield of certain results. For example the operator may suspect that there is a probing issue as the number of failed dies per wafer gradually increases. The disadvantage of the present method is that probing problems usually begin long before they are detected by the operator. This leads to the probing failure of potentially large numbers of dies that are good dies.